1. Field of the Invention
The present invention relates to an organic film vapor deposition method for depositing a moisture-resistant protective film onto a scintillator panel for medical X-ray photography or the like and the scintillator panel made by this method.
2. Related Background Art
While X-ray sensitive films have been used in medical and industrial X-ray photography, radiation imaging systems using radiation detecting devices have been coming into wider use from the viewpoint of convenience and their storability of photographed results. In such a radiation imaging system, pixel data caused by two-dimensional radiation are acquired by a radiation detecting device as an electric signal, which is then processed by a processing unit, so as to be displayed onto a monitor.
Conventionally known typical radiation detecting devices include those disclosed in Japanese Patent Application Laid-Open No. HEI5-196742 and No. SHO63-215987. Such a radiation detecting device forms a scintillator on an imaging device or FOP, such that the radiation incident thereon from the scintillator side is converted by the scintillator into light, so as to be detected.
Here, CsI, which is a typical scintillator material, is high in moisture absorbency and deliquesces by absorbing vapor (moisture) in the air, thereby deteriorating characteristics of the scintillator such as the resolution in particular. Therefore, a moisture-resistant barrier impermeable to water is formed on the upper side of the scintillator layer in the above-mentioned radiation detecting device, so as to protect the scintillator against the moisture.
While a polyparaxylylene film or the like is in use as the moisture-resistant barrier for protecting the scintillator against the moisture, this polyparaxylylene film is deposited by CVD method (vapor phase growth method). When depositing a polyparaxylylene film by CVD method, a planar vapor deposition table or meshed vapor deposition table in a state where a substrate formed with a scintillator is mounted thereon is put into a vapor deposition chamber of a vapor deposition apparatus, whereby the polyparaxylylene film is deposited.
When the polyparaxylylene film is deposited by the above-mentioned method, however, the polyparaxylylene film is formed not only on the substrate but also on the vapor deposition table, whereby the substrate is harder to take up from the vapor deposition table, and it has been impossible for the polyparaxylylene film to be formed over all surfaces of the substrate formed with the scintillator.
It is an object of the present invention to provide an organic film vapor deposition method for depositing an organic film for protecting a scintillator panel onto all surfaces of a substrate formed with a scintillator.
The present invention is characterized in that it comprises a first step of supporting a substrate formed with a scintillator on at least three protrusions of a target-support element disposed on a vapor deposition table so as to keep a distance from the vapor deposition table; a second step of introducing the vapor deposition table having the substrate supported by the target-support element into a vapor deposition chamber of a CVD apparatus; and a third step of depositing an organic film by CVD method onto all surfaces of the substrate, provided with the scintillator, introduced into the vapor deposition chamber in a state that said substrate is supported so as to keep a distance from said vapor deposition table.
According to the present invention, since the substrate is supported away from the vapor deposition table by the target-support element disposed on the vapor deposition table, the organic film can also be deposited onto the underside of the substrate supported by the sample support, whereby the organic film can be deposited on all surfaces of the substrate including the scintillator by CVD method. Also, the substrate can easily be taken up from the vapor deposition table after the organic film is deposited thereon.
The target-support element of the present invention is characterized in that it is constituted by at least three target-support needles. Also, the target-support is characterized in that it is constituted by a strand member.
Also, the present invention is characterized in that the organic film in the organic film vapor deposition method is a polyparaxylylene film. According to the present invention, the polyparaxylylene film can be deposited on all surfaces of the substrate provided with the scintillator by CVD method.
A scintillator panel according to the present invention having organic film deposited by the above-mentioned method.
This scintillator panel comprises a substrate, a scintillator formed on the substrate, and an organic film covered substantial all surfaces of the substrate not only over the scintillator side but also over the opposite side. This scintillator panel has good moisture-resistant performance.
The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given byway of illustration only and are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.